Air conditioning apparatus



1943- 7 A H. EBERHART; ,335,0

AIR CONDITIONING APPARATUS Filed April 25 1941 INVENTQE' RE-rauz H. Ea:Rn'RR-r.

Patented Dec. 7, 1943 AIR CONDITIONING APPARATUS Arthur H. Eberhart, Springfield, Mass, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a, corporation of Pennsylvania UNITED STATES, PATENT OFFICE Application April 23, 1941, Serial No. 389,833

2 Claims.

is desirable to superheat the vaporized refriger- -ant after it has left the accumulator, in order to evaporate all the liquid particles entrained in the refrigerant, so as to avoid liquid refrigerant entering the compressor.

evaporator coil structure.

this application, in which:

structure.

the air-cooling unit. Plates or fins l9 provide extended heat transfer surfaces for the tubes is and iii. In the illustrated embodiment, the plates 69 are common to all nine tubes. each plate having nine openings through which the tubes extend.

As shown in Fig. 1, the seven evaporator tubes l are connected in series by means of U-bends 2i), and these tubes constitute the evaporator of the refrigerant circuit. The outlet end of the The condenser. l3

A fan 26,

The flow of air By this However, the finer liquid particles remain entrained 10 last evaporator tube is connected through a conduit it to the inlet of the reservoir or accumu- The object of the present invention is to prolator M. The two superheater tubes iii are convide an improved apparatus for superheating the nected in series by means of a U-bend 2 and a refrigerant discharged from the accumulator, 'a conduit 23 connects the accumulator H with the more Particular je t e g to provide appa- 5 inlet end of the first of the two superheater tubes. ratus which may be made at reduced cost. The outlet end of the second superheater tube is In accordancewith my invention, the vaporconnected to a suction conduit 24 which extends ized refrigerant discharged from the accumulator to the motor-compressor unit i2. is passed through one or two superheater tubes The remainder ofthe refrigerating system may which are so arranged-that the stream of air be of conventional character. flowing over the evaporator tubes also flows over may be an ailrcooled Cross-finned Whlch the superheater tube or tubes to superheat the case a fan 25 is preferably provided for circulatrefrigerant flowing therethrough. In the pre- 111g y ta c n Such as Outdoor ferredembodiment of my invention, the super over the surfaces of the condens heater tube or tubes are incorporated in the 25 preferably driven by an electric motor 21, c1rcu lates the air to be cooled over the surfaces of the These and other objects are eiiected by my inplates I8 and the outer surfaces of the, tubes of ention as will be apparent from the following the evaporator coil structure l0.

description and claims taken in connection with over the evaporator coil structure ID, as seen in the accompanying drawing, forming a part of Fig. 1, is from right to left, so that the two superheater tubes are contacted by the relatively Fig. 1 is adiagrammatic view of air cooling apwarm air. paratusincorporatingmy invention; Operation Fig. 2 is a front elevation of the evaporator 0011 w The refrigerant is compressed by the motor Referring to the drawing in detail, I show a 0d compressor unit and discharged to refrigerating ystem which is adated f r cooling denser l3, wherein it is condensed by the air cirair and which incorporates my invention. I deculated moreover by the j The condensflad sire it to be understood that this refrigerating refrigerant enters caplllary tube Wherem system may be incorporated in a portable self- 40 it is p n d and 5 P s e du om contained unit, as is Well known in the art. The t e l t e pa de eg g nt flows refri eratings stem comprises generally an evapthrong 6 S ven ev po Or 11 BS i j 'orato r structuie II), a. reservoir or accumulator and as 115 flows through the same, the llquld e- H, e, motor-compressor unit n a condenser 3 frigerant is vaporized by the heat extracted from and an elongated tube l4 of restricted bore, comthe air n e t e v p r t uct emonly refe d t as a capil'lary tuba The vaporized refrigerant is then conveyed by Referring in greater detail to the evaporator the conduit 2| to the accumulator l. structure ID, it is of the cross-finned serpentine time, most of the refrlgfirant S apo la d- Howcoil type. In the illustrated embodiment, it comever, it usually contains s fine hquid parti l s prises nine 'straight tubes-seven evaporator soentralned p t ap ri efrlgerant, a d also tubes [5 and two superheater tubes l6extendlarger p s' Q qu y be earned i o the i b t and supported by d plates l1, accumulator during change in the operating con- The latter are formed with flanges l8, whereby dl'tions. Any liquid particles of substantial size the evaporator structure is suitably mounted in are retained within the accumulator ll.

in the vaporized refrigerant and are conveyed through the conduit 23 to the superheater tubes i6. In the latter, these liquid particles are fully vaporized and the vaporized refrigerant is superheated by the relatively warm air circulated over the superheater tubes It by the fan 28. The superheated refrigerant vapor then flows through the suction conduit 26 to the motor-compressor unit [2 to he recompressed.

By superheating the. vaporized refrigerant and fully vaporizing any liquid particles in the superheater tubes, the possibility of any liquid refrigerant entering the motor-compressor unit it is eliminated. Furthermore, condensation of moishire on the suction conduit to is substantially or completely eliminated.

While it is not new to superheat the vaporized refrigerant leaving the accumulator, I believe it to be new to do so by'means of a tube or tubes in the evaporator structure by heat extracted from the air flowing over the evaporator structure. This arrangement may be provided at lower cost than arrangements previously known.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and-modifications without departing from the spirit thereof, and I desire, there-- fore, that only such'limitations shall be placed thereupon as are specifically set forthin the appended claims.

What I claim is: 1. In a unit air cooler, the combination of a compressor, a condenser, a constantly-open expansion device of constant restriction comprisinga capillary tube, an evaporator of the dry type comprising a plurality of tubes, said tubes being connected in series and in such manner that the refrigerant flows therethrough at substantial velocity and but once before returning to the compressor, a reservoir or accumulator connected to the outlet end of the evaporator to receive the refrigerant leaving the same and being adapted to retain therein any liquid particles of substantial size, a's'uperheater tube or tubes connected to said reservoir or accumulator and receiving the vaporized refrigerant and fine liquid particles of refrigerant entrained therein, and means for effecting flow of a common stream of air over the evaporator tubes and said superheater tube or tubes, said superheater tube or tubes serving to :vaporize said fine liquid particles of refrigerant entrained in the vaporized refrigerant and to superheat said vaporized refrigerant.

2. A unit air cooler as set forth in claim 1, Whereinsaid evaporator tubes and said superheater tube or tubes are incorporated in a unitary coil structure. 

